Driver assistance systems (ADAS: Advanced Driver Assistance Systems) and navigation systems for the automation of driving functions in motor vehicles are becoming increasingly important. One aim of this is ultimately to enable largely automatic driving of the vehicle by detecting information about the surroundings of the vehicle by means of a close-range sensor system and a current position determination and by virtue of road features determined from digitalized two-dimensional or three-dimensional maps. By the calculation of driving times and distances to a destination and with support for the driver along a selected driving route, as well as by auxiliary aids such as traffic space monitoring, hazard warnings, lane assistance, distance assistance and emergency intervention controls, such systems contribute toward the continual improvement of road safety and traffic flow, and to the reduction of energy consumption when operating the motor vehicle.
DE 103 27 255 A1 describes an automatic control device for a vehicle, in which a nominal arrival time at a destination is specified. With reference to the distance from the destination at the time, which can be determined with the help of a navigation system, a nominal speed is calculated and the vehicle's speed is correspondingly controlled in relation to it.
From DE 103 35 927 B4 a navigation system of a motor vehicle and a method for determining a travel route are known, with which a maximum expected driving time between a starting point and a destination are specified. Out of a number of different possible routes, that with the probably lowest fuel consumption is chosen. To calculate that route in advance, nominal speeds are determined for individual road sections, and for this topological features such as uphill and downhill gradients and routes along the road sections are taken into account.
DE 10 2005 050 753 A1 describes an automatic control system of a motor vehicle with a navigation system, with which a driving resistance profile of a stretch ahead is determined. From this a strategy for driving along the stretch is developed, on the basis of which the transmission gear ratio is adjusted, a control unit for the drive motor is re-parameterized or an auxiliary drive is brought into play. The re-parameterization of the control data in the control unit of the drive motor is done in such manner that the motor is operated with emissions and consumption as low as possible. The user can input specifications such as the fastest, or else the most energy-saving travel mode along the stretch.
From DE 10 2007 027 133 A1 a navigation system and a method for reaching a destination at a desired arrival time are known, in which during the journey the current position of the vehicle is regularly compared with a position which, in accordance with an expected speed, the vehicle should have reached. By means of the navigation system, if there is a difference between these, then a speed recommendation permissible within the legal limits is issued such that the vehicle will reach its destination neither sooner, nor later than the desired arrival time. A current, actually permissible maximum speed or a speed to be expected having regard to traffic hold-ups can be interrogated by an external service-provider and imported into the navigation system.
DE 10 2008 005 328 A1 describes a method for the energy-efficient operation of a motor vehicle with a navigation system and a driver assistance system for controlling speeds and distances, and also with means for detecting the surroundings of a vehicle, wherein a travel route with a low fuel consumption is selected and topographical, traffic-situation, meteorological or load-relevant data are taken into account. During the journey, as a function of these data and also as a function of current information about objects that are moving in front of the vehicle and should be taken into account, an energy-saving operating mode of the vehicle is determined and/or an energy-saving route is adapted. The energy-saving operating mode can include the adjustment of a transmission ratio, coasting operation with the transmission idling, or a speed reduction in order to avoid unnecessary braking operations.